Efficacy and safety of nutrition therapy for patients undergoing abdominal surgery: a systematic review and network meta-analysis

The incidence of malnutrition in patients undergoing abdominal surgery exceeds 50%, and postoperative nutritional support is crucial for improving patient outcomes. While Enhanced Recovery After Surgery (ERAS) protocols highlight early nutrition support, their impact on different nutritional strategies remains unclear. This study assessed the effects and safety of enteral nutrition (EN), early-supplemental parenteral nutrition (E-SPN), late-supplemental parenteral nutrition (L-SPN), and total parenteral nutrition (TPN) through network meta-analysis. Three databases were searched to obtain randomized controlled trials involving four interventions for postoperative nutritional supportive therapy in abdominal surgical patients. We used The Cochrane Handbook tool (2.0) to assess the risk bias of included studies. The primary outcome was the occurrence of postoperative adverse events. Network meta-analysis was performed using STATA 14. A total of 48 studies involving 6277 patients were included. Network meta-analysis showed that compared with other nutritional therapy E-SPN was likely more effective than other modalities in terms of reduction of postoperative adverse events (OR = 3.02, 95% CI: 1.81-5.02), infectious adverse events (OR = 3.12, 95% CI: 1.59-6.15), non-infectious adverse events (OR = 2.47, 95% CI: 1.14-5.34), shortening the resumption of exhaust time (SMD = 0.98, 95% CI: 0.59-1.36), and improvement of serum albumin (SMD = -2.74, 95% CI: -4.98-0.50). The final surface under the cumulative ranking curve value indicated that E-SPN achieved the best effect in those outcomes. The obtained results support using E-SPN in patients undergoing abdominal surgery, which might reduce adverse events, shorten recovery time, and improve patient outcomes. However, since serum albumin is primarily an inflammatory marker rather than a direct indicator of nutritional status, its role in evaluating SPN benefits should be interpreted with caution. Further research is needed to assess SPN's effectiveness in patients undergoing surgery according to an ERAS protocol.